The new and distinct variety of peach [Prunus persica (L.) Batsch] originated from a cross of xe2x80x98Redhavenxe2x80x99xc3x97(NCA001, NCA002, and NCA003 bulk) made in 1987 at the Sandhills Research Station at Jackson Springs, N.C. NCA001, NCA002, and NCA003 all originated from the 1981 cross of xe2x80x98Reliancexe2x80x99xc3x97xe2x80x98Biscoexe2x80x99. xe2x80x98Biscoexe2x80x99 was released and named as a peach variety by the North Carolina Agricultural Research Service in 1968. xe2x80x98Reliancexe2x80x99 was released by the University of New Hampshire in 1964, and xe2x80x98Redhavenxe2x80x99 was released by Michigan State University in 1940. None of these three varieties are patented, and all are currently available in commerce.
Plants and fruit of this new variety differ phenotypically from its parents. The new variety produces medium, yellow flesh, firm fruit that ripen in early July in North Carolina, about 1 week after xe2x80x98Redhavenxe2x80x99 and xe2x80x98Reliancexe2x80x99, and 3.5 weeks before xe2x80x98Biscoexe2x80x99. The round, smooth fruit have attractive red skin color, the foliage and fruit have high bacterial spot resistance, and the flower buds, flowers and young fruit exhibit high resistance to freezing temperatures. The new variety differs from xe2x80x98Reliancexe2x80x99 in having more attractive fruit skin color, firmer flesh, improved flesh texture, and larger fruit. The new variety differs from xe2x80x98Redhavenxe2x80x99 in having higher resistance of the flower buds to freezing temperatures, and greater resistance to bacterial spot disease.
The approximately 300 seeds resulting from this controlled hybridization were germinated in a greenhouse at North Carolina State University, Raleigh, N.C. in the fall of 1987 and planted in the field in spring of 1988. These trees first produced fruit in 1990, and one seedling, designated NC-C3-68, was selected for its medium, yellow flesh fruit, attractive red color, bacterial spot resistance, low acid fruit, and heavy fruit production.
During 1993 and 1994, the original plant selection was propagated asexually by grafting of vegetative buds onto the standard peach rootstock xe2x80x98Lovellxe2x80x99, at the Sandhills Research Station. xe2x80x98Lovellxe2x80x99 is unpatented and is currently available in commerce. Two grafted trees of the variety were established in test plots at Sandhills Research Station in 1994, and twelve grafted trees of the variety were established at the same station in 1998.
The new variety has routinely been asexually multiplied by grafting, specifically xe2x80x98Txe2x80x99 budding. It readily forms a graft union with peach rootstock and resumes normal growth. During all asexual propagation, the characteristics of the original plant have been maintained and no aberrant phenotypes have appeared.
Test plantings and performance evaluation over seven years at the Sandhills Research Station demonstrate this variety to be consistent in its characteristics, taking into consideration the normal variation in time of flowering and time of ripening associated with yearly climatic variation.
Plants of the new variety are very vigorous and grow rapidly after establishment of trees in the field. Young trees have averaged 2-3 feet of growth per year. Plants are semi-upright in growth habit. Angles between the trunk and main branches average 70 degrees. Flowering sometimes occurs in the second year of growth, but more commonly trees begin flowering in the third year after establishment. Flowers are single, medium pink, and in accordance with typical classification of peach flowers by nurseries and professionals, are classified as non-showy. Flowering usually begins in mid March in Raleigh, N.C.; the chilling requirement is estimated to be 950 hours below 4 C., based on comparison of flowering time to standard varieties.
Fertility of flowers is excellent, and fruit set is generally very high in most years. Flowers are self-fertile. Flowers have shown excellent resistance to cold temperatures during winter dormancy and during flower development in the spring. Trees produced 20% of a full fruit crop in 1996, a year in which all commercial varieties in research plots failed to produce a fruit crop at the Sandhills Research Station because of low temperature injury. In that year, trees in flower were exposed to six consecutive nights of below freezing temperatures from March 9 through March 14, inclusive. Fruit are medium to large, averaging 6.35 cm, yellow fleshed, and show normal acidity typical of peach. Fruit ripen in late June to early July in Jackson Springs, N.C., averaging July 1 over 5 years of observation. Resistance of foliage to bacterial spot disease is excellent. Bacterial spot resistance was assessed over three years of observation in field plots at the Sandhills Research Station, Jackson Springs, N.C. by rating trees for leaf defoliation after natural field infection.
The new variety has been named the CHALLENGER cultivar.